Fire-extinguisher composition



HARRY S. MOEK, OF BBOOKLIHE, MASSACHUSETTS, ASSIGNOR, BY ME ASSIGN- MEETS, '10 AMERICAN LA FRANCE FIRE ENGINE COIEPANY, 1110., OF NEW YORK, A COBPOEA'IIQN E NEW YOBK.

FIBE-EXTING- COOSITION.

' 1,393,236. r Specification of Letters Patent. recant d eat. 11, 1921.

Re Drawing. Awlicatienflled January 14, 1918. Serial No. 211,885.

To all whom it may concern:

Be it known that I, HARRY S. MonK, a citizen of the United States, residing at Brookline, county of Norfolk, State of Massachusetts, have inventeda certain new and useful Fire-Extinguisher Composition, of which .the following is a specification.

My invention relates to fire extinguisher charges and more particularly to the carbonate solution from which carbon dioxid for expelling the extinguishing medium is generated by reaction with a suitable acid. Alkali metal salts of carbonic acid, either in the form of bicarbonate or inthe form of the normal carbonate have been commonly .employed for such solutions, while sulfuric acid or hydrochloric acid has usually been em ploged as the acid charge. In order that the car onatesolution may always-remain in a condition suitable for use even when exposed to low temperatures, it has been proposed to incorponatein the carbonate solution, an ingredient for lowering the freezing point thereof. Most of those ingredients which have been heretofore proposed for this purpose are subject to one disadvantage or another. in some instances, the addition'agent is net suficiently stable, or it tends to give rise to the formation of a precipitate of insoluble carbonate or other salt or to retard the generation or evolution of the carbon dioxid gas; or its effect in small quantities has not been suificiently marked in depressing the freezing point.

The object of my invention is to produce a carbonate solution char e of the desired low freezing point which s all be free from the disadvantages above noted. At the same time, the invention seeks to avoid the use of ingredients vwhich mi ht involve undue expense, or which -woul in any way interfere with the fire extinguishing qualities of the medium which is to be ejected fi'om the apparatus. 1

According to the present invention, the carbonate solution embodyin the ingredients for depressing the freezing oint, exhibits all the good qualities required in a medium of this kind and in addition to having'the desired low freezing point, the solution also has a somewhat increased capacity for generating carbon dioxid due to the resence of the ingredient for lowering the reezing point.

The carbonate solution embraced by-my present mvention comprises as essential ingredients, an alkali metal carbonate and an alkali metal acetate. bonate and potassium acetate are specifically described and claimed in my prior -pplication filed April 11th, 1917, Serial l\o. 161,295, entitled Fire extinguisher charges, but'I claim broadly in the present the potassium salts of carbonic applicatio acid with he alkali metal acetate or alkali The potassium car metal salts of carbonic acid with sodium at ordinary temperatures and has a freezingpoint of approximately 58'F. The solutlon becomes-somewhat pasty at -32 F. 15 cubic centimeters of this solution at 20 C. when treated with 1 0.0. of sulfuric acid of suflicient strength to neutralize twothirds of the bicarbonate showed a total gas evolution of abdht 55cubic centimeters at the end of the first minute, 65 cubic centimeters at the end of the second minute, 71 cubic centimeters at the end of the third minute, 75 cubic centimeters at the end of the fourth minute, and 7 7 1} cubic centimeters at the end of the fifth minute. observed on comparing: this result with the total gas evolution from a similar quantity.

of a solution made up .of 5.53 grams of sodium bicarbonate in 100 cubic centimeters of water, that the gas evolution from the solult will be tion containing the sodium acetate is more complete at the end of the test period than in the case of the solution not embodying the sodium acetate. The sodium bicarbonate and water solution gives from the same test uantity when treated with the same quantlty of sulfuric acid atthe' same temperature, a total gas evolution of about 69. cubic centimeters at the end of the first minute, 71-;- cubic centimeters at the end of the second minute, 72 cubic centimeters at the end of the third minute, 72} cubic centimeters at the end of the fourth minute, and no further increase up to the end of the fifth minute.

A further example of my invention may be represented by a solution of potassium carbonate and sodium acetate in water. A solution made up 4.54 grams of potassium carbonate and 81 grams of sodium acetate crystals in 100 cubic centimeters of water, shows a freez' point of close to 40 F. While this solutlon exhibits the low freezing point stated, it is to be noted that crystals begin to separate when the temperature becomes as low as about -15 F. The evolution of carbon dioxid gas from this solution is somewhat better than that observed in the case of the simple solution of potassium carbonate in water. For example, 15 cubic centimeters of a test solution made up of 4.54 grams of potassium carbonate and 81 grams of sodium acetate crystals in 100 cubic centimeters of water at 20 C. showed under treatment with l c. c. of sulfuric acid of sufiicient strength to neutralize two-thirds of the carbonate, a total gas evolution of about 32 cubic centimeters at the end of the first minute, 33% cubic centimeters at the end of the second minute, 34% cubic centimeters at the end of the third minute, 35%- cubic centimeters at the end of the fourth minute, and 36% cubic centimeters at the end of the fifth minute. The same test quantity of a solution made up of 4.54 grams of potassium carbonate in 100 cubic centimeters of water, showed under similar test a total gas evolution of about 32cubic centimeters at the end of the first inute, 33% cubic centimeters at the end of the second minute, 34% cubic centimeters at theend of the third minute,

water, namely: 6.60'grams of potassium bi-' carbonate with 53.5 grams of'sodium acetate or 53.5 grams of potassium acetate; and 5.21

grams of ammonium bicarbonate .With 53.6 grams of sodium acetate or 53.8 grams of potassium acetate. Good results can still be retained with considerable variation in the proportions given.

Any of the solutions embodied b my invention are well adapted to per orm the functions required of a fire extinguishing medium. They are in practice employed for example as a charge in any approved type of fire extinguisher, in which an acid charge is maintained and may be introduced into the carbonate solution for develo ing the pressure gas of carbon dioxid em dyed for expelling the medium upon the re.

I claim: 1. A carbonate solution for fire extinguishers, comprising as essential ingredients normal potassium acetate.

2. A carbonate solution for fire extinguishers, comprising as essential ingredients normal potassium carbonate and sodium acetate, substantially in the proportions of 4.54 grams of potassium carbonate and 81 grams of sodium acetate, in 100 cubic centimeters of water.

carbonate, and sodium HARRY S. MORK. 

